[jwalden@h-130 js]$ ./js
js> function q()
{
  return new do { function(){this.x = 7;} } while(0)
typein:3: SyntaxError: syntax error:
typein:3:   return new do { function(){this.x = 7;} } while(0)
typein:3: .............^
js> function q()
{
  return new for(;true;false) function(){this.x=7;}
typein:6: SyntaxError: syntax error:
typein:6:   return new for(;true;false) function(){this.x=7;}
typein:6: .............^
js> function q()
{
  return new do function(){this.x=7;} while (0)
typein:9: SyntaxError: syntax error:
typein:9:   return new do function(){this.x=7;} while (0)
typein:9: .............^
js>